In a few months, I will be moving the states in order to start a new company. My european build F01 740d is precious to me so I was thinking to bring it over. However, some google activities reveiled that this is not so straight forward so I am checking here to see of someone maybe has some experience with this process.

No, sorry you cannot bring a European-spec car across the pond even though we sell similar cars. The engine has not undergone US EPA (environmental protection assholes) testings and it cannot be titled here. You used to be able to import grey market cars but not anymore. Trust me, compared to Belgium a 7 series will be WAY cheaper stateside.

Unless you're a diplomat, you will not be able to bring your car here. If it were a gasoline model, you might get it up to spec, but it's very doubtful you'd be able to get a diesel to spec. It would require particulate filters and urea injection.

If you're a diplomat, you probably can. I see all sorts of European vehicles in DC with diplomatic tags that couldn't be here otherwise.